Is there that much of a difference between the A33 and A55 to warrant the extra $150?
Whether the difference justifies the price is one of those questions that has no answer - it's all up to you - however, between those two I'd probably try to work the extra money for the A55 over the A33 if it was feasable, as the 16MP sensor used in the A55 is pretty much the top of the heap in almost every review you can get your hands on, and in samples too (the same 16MP sensor that also resides in the A580, Pentax K5, and Nikon D7000 & D5100). The 14MP sensor in the A33 is also still quite good - still one of the better APS-C sensors you can get...but if I were out there buying, I'd try to squeeze the 16MP sensor into my budget. There's not much else between them - GPS means nothing to me either as a buying decision. It would all be the sensor - and really might only be a big impact on you if you shoot a lot of high ISO work...otherwise the A33 sensor is likely still everything you'd need.
And I read that Minolta lenses work with the A33/A55. Is it all or just a select few?
It's pretty much any Minolta lens with autofocus, which is to say any Minolta lens made since about 1985 or so when they went to autofocus. These all are from the SLR line called 'Maxxum' - the only thing you might occasionally run into are lenses for a system called 'Vectis' - these will not work as they are from a different camera system that was only made for a very small time - you'll likely not run into very many though - there are many hundreds of Maxxum/AF/A-mount Minolta lenses which you'll find almost all the time. Stay away from MD mount lenses, which are the manual focus variety, as these will not work on the Sony bodies without adapters.
What are some good wesbites that sell the Minolta lenses?
The best source for used lenses that can be relied on is KEH.com...they have a good selection of Minolta mount lenses and get them in all the time - they are all very reliably rated with return guarantees. B&H, Adorama, eBay,
Amazon, and other sources exist. Also, check out the forums at the site Dyxum.com...this is a forum for all things Minolta, and they have a Buy/Sell forum page.
